Tea Or Coffee, Which do you prefer to drink? 思辨好文

Countless arguments have been waged over the
superiority of one beverage over the other. But what does the scientific
evidence say?

By David Robson

15 January 2016

George Orwell may have written that “tea is one of
the mainstays of civilization in this country” – but even we British have to
acknowledge that our national drink is facing stiff competition from the
espressos, cappuccinos, and lattes invading our shores.

Despite the dangers of wading into such a charged
argument, BBC Future decided to weigh up the relative merits of each drink.
There’s no accounting for taste, of course, but we have combed the scientific
literature for their real, measurable effects on our body and mind.

The wake-up callFor many, the caffeine
kick is the primary reason we choose either beverage; it’s the oil to our
engines when we’re still feeling a bit creaky in the morning. Based purely on
its composition, coffee should win hands down: a cup of tea has about half the
dose (40 milligrams) of the stimulant caffeine that you would find in a
standard cup of brewed filter coffee (80 to 115 milligrams). Yet this doesn’t
necessarily reflect the jolt of the wake-up call.

Caffeine dose is not the
whole story: perhaps our expectations also determine how alert we feel

The scientists conclude that the caffeine dose is
not the whole story: perhaps our expectations also determine how alert we feel,
or it could be that it’s the overall experience of the tastes, and smells, of
our favourite drink that awakens our senses.

Verdict: Against logic,
tea seems to provide just as powerful a wake-up call as coffee. It’s a draw.

Sleep qualityThe biggest differences
between coffee and tea may emerge once your head hits the pillow.

University of Surrey researchers found that coffee drinkers tend to
find it harder to drop off to sleep at night (Credit: iStock)

Comparing people drinking the same volume of tea
or coffee over a single day, researchers at the University
of Surrey in the UK confirmed
that although both drinks lend similar benefits to your attention during the
day,coffee drinkers tend to find it harder to drop off at night– perhaps because the higher caffeine content
finally catches up with you.

Tea drinkers, in contrast, had longer and more
restful slumbers.

Verdict: Tea offers
many of the benefits of coffee, without the sleepless nights – a clear win.

Tooth stainingAlong with red wine,
coffee and tea are both known to turn our pearly whites a murky yellow and
brown. But which is worse?

Verdict: If you want a
perfect smile, coffee may be the lesser of two evils.

A balm for troubled
souls…In England, it’s
common to give “tea and sympathy” to a distressed friend – the idea being that
a cup of Earl Grey is medicine for troubled minds. In fact, there is some
evidence that tea can soothe your nerves: regular tea drinkers do tendto show a calmer physiological response to unsettling situations(such as public speaking), compared to people
drinking herbal infusions. Overall, people who drink three cups a day appear to
havea 37% lowerrisk
of depression than those who do not drink tea.

There is some evidence
that tea can soothe your nerves

Coffee doesn’t have the same reputation; indeed,
some report that it makes them feel like their nerves are jangling. Yet there
is some evidence that it too may protect against long-term mental health
problems. A recent “meta-analysis” (summarising the results of studies
involving more than 300,000 participants) found that each cup of coffee a day
seems to reduceyour risk of developing depression by around 8%.In contrast, other beverages (such as sweetened
soft drinks) only increase your risk of developing mental health problems.

University of Surrey researchers found that coffee drinkers tend to
find it harder to drop off to sleep at night (Credit: iStock)

We need to take such results with a pinch of salt:
despite the scientists’ best efforts, in this kind of large epidemiological
study it’s hard to rule out other factors that may be behind the link – but it
could be that both drinks offer a cocktail of nutrients that dampen down stress
responses and boost mood in the long-term.

Verdict: Based on this
limited evidence, it’s a draw.

…and a balm for bodiesSimilarly tantalising,
though preliminary, epidemiological studies have suggested that both coffee and
tea offer many other health-giving benefits. A few cups of either beverage a
day appears to reduce your risk of diabetes, for instance. (The exact size of
the benefit is still under discussion – estimates vary fromaround 5 to 40%.) Since even decaf coffee confers the same
benefits, it seems likely that other nutrients may be oiling the metabolism so
that it can still efficiently process blood glucose without becoming
insensitive to insulin – the cause of diabetes.

A few cups of either
beverage a day appears to reduce your risk of diabetes

Both drinks also seem to moderatelyprotect the heart, although the evidence seems to be
slightly stronger for coffee, while tea also appears to be slightly protective
againstdeveloping a range of cancers– perhaps because of its antioxidants.

Verdict: Another draw –
both drinks are a surprising, health-giving elixir.

Overall verdict: Much
as we Brits would have liked tea to come out the clear victor, we have to admit
there is little between the two drinks besides personal taste. Based solely on
the fact that it allows you to get a better night’s sleep, we declare tea the
winner – but why not share your own thoughts with us through social media?